The invention relates to a clutch, preferably a multi-disc clutch between an internal combustion engine and a transmission, which are incorporated in a motor vehicle, the clutch comprising driving disks and transmission disks.
A clutch of the type above is known from U.S. Pat. No. 4,846,326 and U.S. Pat. No. Re. 36,363 and is provided with driving disks and transmission disks of carbon. Investigations have shown that, when the driving disks as well as the transmission disks of the clutch consist of carbon, comfort disadvantages, which appear as interfering shudder during starting processes, occur when such clutches are used in serially produced motor vehicles. 
U.S. Pat. No. 5,452,728 discloses clutch disks, between which separating disks of steel are provided. The separating disks are provided with a layer of ceramic.
U.S. Pat. No. 5,452,784 deals with a multi-disc clutch, the driving disks and transmission disks of which have a thin film of ceramic on the mutually facing surfaces.
An aspect of the invention is to construct driving disks and transmission disks of a clutch, disposed between the internal combustion engine and the transmission of a motor vehicle, in such a manner by a selective configuration, that the clutch, at a high torque transfer and wear resistance, is distinguished by an optimized operational capability with respect to the function.
Pursuant to certain preferred embodiments of the invention, this aspect may be accomplished in that the driving disks (2, 3, 4 and 5) and the transmission disks (6 and 7), at least in a region of friction sections (RaI, RaII, RaIII, RaIV, RaV, RaVI, RaVII and RaVIII) are formed in such a manner, that the friction sections are largely shudder insensitive.
Advantages, achieved with certain preferred embodiments of the invention, are to be seen therein that, due to a selective development of the driving disks and of the transmission disks or their friction sections of the clutch, the latter not only securely transmits torque and is wear resistant, but is also largely insensitive to shudder and, with that, renders a contribution to improving comfort. Moreover, due to a defined selection of materials for the driving disks and the transmission disks or their friction sections, a decreasing coefficient of friction is developed during their interaction. The materials of the driving disks and of the transmission disks, optionally only the friction surfaces of the latter, have, on the one hand, a high wear resistance and speed stability and, on the other, a high coefficient of friction and a high thermal stability. Moreover, the clutch is optimized thereby if, for example, the driving disks are made of a ceramic with a fiber fabric and the transmission disks are made of a sintered, organically bounded material. The latter material, especially, has compressible properties, which support comfortable interaction between the driving disks and the transmission disks.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.